CN114901403B

CN114901403B - Transducer for generating a vibrating movement

Info

Publication number: CN114901403B
Application number: CN202080083147.5A
Authority: CN
Inventors: 尼古拉斯·井上
Original assignee: Ground Wave Co ltd
Current assignee: Ground Wave Co ltd
Priority date: 2019-11-29
Filing date: 2020-11-27
Publication date: 2024-02-20
Anticipated expiration: 2040-11-27
Also published as: GB2591982A; EP4065292A1; KR20220101737A; WO2021105456A1; GB201917525D0; US20230117699A1; CN114901403A; JP2023504483A

Abstract

The present specification describes a transducer configured to convert an electrical signal into vibratory motion. The transducer includes an axially magnetized reciprocating magnet magnetically suspended between first and second axially magnetized fixed magnets located on opposite sides of the axially magnetized reciprocating magnet, wherein the axially magnetized reciprocating magnet includes an aperture such that the reciprocating magnet has an inner boundary and an outer boundary. The transducer further includes at least two concentrically positioned pairs of electromagnetic solenoids configured to drive the reciprocating magnet to reciprocate in a volume between the first and second axially magnetized fixed magnets. The first solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is positioned to affect the reciprocating magnet more at the inner boundary than at the outer boundary, and the second solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is positioned to affect the reciprocating magnet more at the outer boundary than at the inner boundary.

Description

Transducer for generating a vibrating movement

Technical Field

The present specification relates generally to a transducer for producing vibratory motion. More particularly, the present description relates to a transducer suitable for incorporation into portable applications such as footwear.

Background

The use of vibration to stimulate the human sense of touch is a field of haptic technology. As more and more products evolve to include haptics, there is a need for transducers that are compact and efficient but that also provide good low frequency response.

Because a person's foot is particularly sensitive to touch, it is particularly desirable to provide footwear that is associated with the sense of touch (i.e., footwear that can transfer vibrations to the wearer's foot). However, transducers that provide good low frequency response are generally not well suited for use in footwear in terms of size or shape.

Disclosure of Invention

The invention is defined by the claims.

In a first aspect, the present specification describes a transducer configured to convert an electrical signal into vibratory motion. The transducer includes an axially magnetized reciprocating magnet magnetically suspended between first and second axially magnetized fixed magnets located on opposite sides of the axially magnetized reciprocating magnet, wherein the axially magnetized reciprocating magnet includes an aperture such that the reciprocating magnet has an inner boundary and an outer boundary. The transducer further includes at least two concentrically positioned pairs of electromagnetic solenoids configured to drive the reciprocating magnet to reciprocate in a volume between the first and second axially magnetized fixed magnets. The first solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is positioned to affect the reciprocating magnet more at the inner boundary than at the outer boundary, and the second solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is positioned to affect the reciprocating magnet more at the outer boundary than at the inner boundary. The first solenoid of each of the concentrically positioned pairs of electromagnetic solenoids may be located within the bore of the reciprocating magnet and the second solenoid of each of the concentrically positioned pairs of electromagnetic solenoids may be located outside the outer boundary of the reciprocating magnet when viewed along the axis of reciprocation of the axially magnetized reciprocating magnet.

The transducer may include a central guide member, wherein the volume of the reciprocating ring magnet driven for reciprocation surrounds the central guide member and the central guide member extends through the bore of the reciprocating magnet, and at least two concentrically positioned pairs of electromagnetic solenoids are configured to drive the reciprocating magnet for reciprocation along the length of the central guide member. The transducer may further comprise an outer guide member surrounding and defining an outer boundary of the volume in which the reciprocating magnet is driven for reciprocating motion. The outer surface of the center guide member adjacent to the inner boundary of the reciprocating magnet and the inner surface of the outer guide member adjacent to the outer boundary of the reciprocating magnet may be formed of a material that reduces friction between the reciprocating magnet and the center guide member and the outer guide member. The second solenoid of each of the concentrically positioned pairs of electromagnetic solenoids may be located within or form part of the outer guide member. The first solenoid of each of the concentrically positioned pairs of electromagnetic solenoids may be located within or form part of the central guide member.

The central guide member may include a central guide member fluid passage extending through a central region of the central guide member to allow fluid to flow through the central region of the central guide member between a first end of the central guide member and a second end of the central guide member.

The transducer may further comprise at least one second fluid channel configured to allow fluid to pass between a volume in which the axially magnetized reciprocating magnet is driven for reciprocating movement and the first end of the central guide member fluid channel. The transducer may further comprise at least one third fluid channel configured to allow fluid to flow between a volume in which the axially magnetized reciprocating magnet is driven for reciprocating movement and the second end of the central guide member fluid channel. The transducer may be sealed.

The transducer may include a vibration absorbing material disposed between the axially magnetized fixed magnet and the reciprocating magnet. The vibration absorbing material may be provided on a surface of the axially magnetized fixed magnet facing the reciprocating magnet. Alternatively, the vibration absorbing material may be provided on a surface of the reciprocating magnet facing the axially magnetized fixed magnet.

The transducer may include a magnetic shield to magnetically shield the environment surrounding the transducer from the magnets of the transducer.

The reciprocating magnet may include: a first main surface facing the first axially magnetized fixed magnet; a second main surface facing the second axially magnetized fixed magnet; an inner surface extending between the first and second major surfaces at an inner boundary of the reciprocating magnet; and an outer surface extending between the first major surface and the second major surface at an outer boundary of the reciprocating magnet. Furthermore: an edge of a first solenoid in a first one of the concentrically positioned pairs of electromagnetic solenoids may be positioned adjacent to an edge of the reciprocating magnet connecting the first major surface and the inner surface; an edge of a first solenoid in a second of the concentrically positioned pairs of electromagnetic solenoids may be positioned adjacent to an edge of the reciprocating magnet connecting the second major surface and the inner surface; an edge of a second solenoid in a first of the concentrically positioned pairs of electromagnetic solenoids may be positioned adjacent to an edge of the reciprocating magnet connecting the first major surface and the outer surface; and an edge of a second solenoid in a second one of the concentrically positioned pairs of electromagnetic solenoids may be positioned adjacent to an edge of the reciprocating magnet connecting the second major surface and the outer surface.

In a second aspect, the present specification describes an article of footwear comprising a transducer as described with reference to the first aspect. The article of footwear may also include an amplifier positioned adjacent to the transducer and configured to provide an electrical signal to the transducer. The article of footwear may also include a removable module including a battery pack and a transceiver for receiving wireless signals, the electrical signals provided to the transducer being generated based on the wireless signals.

In a third aspect, the present specification describes a haptic stimulation system comprising: a first vibration device and a second vibration device. The first vibration device includes: a first transducer configured to convert a first electrical signal into a vibratory motion; a first wireless receiver configured to wirelessly receive a first data signal transmitted via a first communication protocol; a first wireless transmitter configured to wirelessly transmit second data signals via a different second communication protocol; and a first processing device configured to: a first electrical signal is generated based on the wirelessly received first data signal and provided to the first transducer, and a second data signal is generated based on the wirelessly received first data signal and provided to the first wireless transmitter for transmission by the first wireless transmitter. The second vibration device includes: a second transducer configured to convert a second electrical signal into vibratory motion; a second wireless receiver configured to wirelessly receive a second data signal transmitted by a first wireless transmitter of the first vibratory device via a second communication protocol; and a second processing device configured to: a second electrical signal is generated based on the wirelessly received second data signal and provided to the second transducer. The first electrical signal and the second electrical signal cause the first transducer and the second transducer to vibrate at substantially the same frequency response.

The haptic stimulus system may further comprise an audio player or an accessory to an audio player, wherein the audio player or accessory to an audio player comprises: a second wireless transmitter configured to wirelessly transmit a first data signal to a first wireless receiver at the first vibration device via a first communication protocol, the first data signal generated based on the audio data signal output by the audio player; and a third wireless transmitter configured to wirelessly transmit the second data signal to the audio speaker. The third wireless transmitter may be configured to wirelessly transmit the first data signal to the audio speaker via the first communication protocol. The first communication protocol may be a bluetooth protocol and/or the second communication protocol may be an RF UHF communication protocol.

Each of the first transducer and the second transducer of the tactile stimulation system may be a transducer as described in relation to the first aspect. The first vibratory device may be disposed in a first article of footwear of a pair of articles of footwear and the second vibratory device may be disposed in a second article of footwear of the pair of articles of footwear.

Drawings

For a better understanding of the apparatus and methods described herein, reference will now be made, by way of example, to the accompanying drawings in which:

FIGS. 1a and 1b show two views of a transducer configured to convert an electrical signal into vibratory motion;

FIGS. 2a and 2B illustrate two views of the oscillating fluid motion within a transducer when the transducer is operating in an exemplary configuration such as that of FIGS. 1A and 1B;

FIGS. 3 a-3 h illustrate a configuration variation of a fluid pathway that may be provided in a transducer such as that of FIGS. 1A and 1B;

FIG. 4 is a simplified setup diagram depicting the magnetomotive force of a reciprocating magnet under the influence of two concentrically positioned electromagnetic solenoid pairs and the natural resting position of a ring magnet within such energized solenoid configuration;

fig. 5a to 5f depict a variation of the structure of a magnetic spring levitation system for levitating a reciprocating magnet in the configuration of fig. 1A and 1B, for example.

FIGS. 6 a-6 c illustrate how the offset distance of a reciprocating magnet is optimized in a configuration such as that of FIGS. 1A and 1B to improve the efficiency of the transducer in converting electrical signals into vibratory motion and to change the frequency response;

FIG. 7 is a diagram of an exemplary method of magnetically shielding a transducer in a configuration such as that of FIGS. 1A and 1B;

FIGS. 8a and 8b illustrate examples in which a plurality of concentrically placed reciprocating magnets may be provided in a transducer according to the concepts described herein in order to provide a transducer with a boundary frequency response;

FIG. 9 illustrates an exemplary configuration of an article of footwear adapted to receive a transducer as described herein;

fig. 10 a-10 c depict examples of systems for wirelessly and simultaneously transmitting audio input from a device to a pair of shoes and a wireless headset, wherein each shoe includes a transducer as described herein.

Detailed Description

Like reference numerals refer to like elements throughout the description and drawings.

The present description relates generally to a transducer that has a good low frequency response and is configured to be integrated into footwear to provide vibration stimulation to a user based on an input audio signal (e.g., an audio component of a musical composition or AV content such as a movie or video game).

Fig. 1a and 1b show examples of such transducers 100, fig. 1a and 1b each showing a different view of the transducer 100.

The transducer 100 comprises an axially magnetized reciprocating magnet 101, the axially magnetized reciprocating magnet 101 being magnetically suspended between first and second axially magnetized fixed magnets 102-a, 102-B located on opposite sides of the axially magnetized reciprocating magnet 101. The pole orientations of the fixed magnets 102-a, 102-B are selected such that they repel either side of the axially magnetized reciprocating magnet 101, thereby forming a magnetic spring assembly whereby the reciprocating magnet stays (i.e., floats) in an equilibrium position between the two fixed magnets 102-a, 102-B. Since these fixed magnets are arranged to repel the reciprocating magnet 101, they may be referred to as repulsive magnetic spring magnets or simply repulsive magnets.

The axially magnetized reciprocating magnet 101 comprises a bore such that the reciprocating magnet has an inner boundary and an outer boundary. One possible form of reciprocating magnet that has been shown in the drawings is in the form of a ring magnet (and reciprocating magnets may sometimes be referred to herein as ring magnets). While there are benefits associated with using ring magnets, other configurations of reciprocating magnets may be used. For example, the outer boundary/perimeter of the ring magnet may be square, hexagonal, or any other shape. The inner boundary/perimeter may have the same shape as at the outer boundary or may have a different shape. To ensure that the transducer is shallower in depth, it is desirable that the diameter/width of the reciprocating magnet be greater than the depth. In some particular embodiments, which have been found to work well, the reciprocating ring magnet 101 has a diameter of about 50 mm. However, the applicability of the concepts described herein is certainly not limited to the use of reciprocating magnets having such diameters.

The transducer 100 also includes at least two concentrically positioned pairs of electromagnetic solenoids 104-A, 105A and 104-B, 105-B. These two pairs may be referred to as an upper pair and a lower pair, wherein both solenoids of a particular pair are located on the same side of the reciprocating magnet 101. These solenoids are configured to drive the reciprocating magnet 101 in a reciprocating motion in a volume between the first and second axially magnetized fixed magnets 102-a, 102-B. More specifically, the first solenoid 104-a, 104-B of each of the concentrically positioned pairs of electromagnetic solenoids (which may be referred to as the inner solenoid of the pair) is positioned to affect the reciprocating magnet 101 more at the inner boundary than at the outer boundary, and the second solenoid 105-a, 105-B of each of the concentrically positioned pairs of electromagnetic solenoids (which may be referred to as the outer solenoid of the pair) is positioned to affect the reciprocating magnet more at the outer boundary than at the inner boundary. The first (inner) solenoid 104-a, 104-B of each of the concentrically positioned pairs of electromagnetic solenoids is located within the bore of the reciprocating magnet 101 and the second (outer) solenoid 105-a, 105-B of each of the concentrically positioned pairs of electromagnetic solenoids is located outside the outer boundary of the reciprocating magnet 101 when viewed along the axis of reciprocation of the axially magnetized reciprocating magnet.

In some examples, each solenoid may include a single coil of conductive material (e.g., wire). However, solenoids may have any suitable form as long as they perform their function of driving the reciprocating magnet in the manner described herein.

The aperture provided in the reciprocating magnet provides two edges of the magnet that can be affected by each of the solenoid pairs. Conversely, if the reciprocating magnet does not have a central bore, only one edge of the magnet, the outer boundary, may be affected. This increases the response capability of the transducer and allows the use of heavier magnets for a given usable axial length, thereby improving the performance of the transducer at low frequencies. This also provides for higher efficiency of the transducer such that a larger area of the reciprocating ring magnet 101 is affected by the solenoid.

It may be beneficial to place the inner axial surface extent of the solenoid at a closer distance from the outer axial surface extent of the ring magnet 101. This enables the transducer to benefit from the highest magnetic flux area of both the reciprocating magnet 101 and the solenoid. Above and below the equilibrium position of the reciprocating ring magnet 101, two solenoid pairs are concentrically placed at a short axial distance, providing four magnetically affected areas to the reciprocating magnet 101. In other words, one solenoid pair is provided on one side of the reciprocating magnet axis and a second solenoid pair 105-b, 104-b is provided on the opposite side. In other words, an edge of a first solenoid in a first one of the concentrically positioned pairs of electromagnetic solenoids is positioned adjacent to an edge of the reciprocating magnet that connects a first major surface of the reciprocating magnet facing the first axially magnetized fixed magnet and an inner surface of the reciprocating magnet at an inner boundary of the reciprocating magnet that extends between the first major surface and a second major surface of the reciprocating magnet facing the second axially magnetized fixed magnet. Further, an edge of a first solenoid in a second of the concentrically positioned pairs of electromagnetic solenoids is positioned adjacent to an edge of the reciprocating magnet connecting the second major surface and the inner surface of the solenoid. Further, an edge of the second solenoid of the first of the concentrically positioned pairs of electromagnetic solenoids is positioned adjacent to an edge of the reciprocating magnet connecting the first major surface and an outer surface extending between the first major surface and the second major surface at an outer boundary of the reciprocating magnet. Further, an edge of a second solenoid in a second one of the concentrically positioned pairs of electromagnetic solenoids may be positioned adjacent to an edge of the reciprocating magnet connecting the second major surface and the outer surface.

The two inner solenoids 104-a, 104-B are separated by a center spacer 110 and the two outer solenoids 105-a, 105-B are separated by an outer spacer 111. Thus, the height of the center shim and the outer shim define the axial distance between the reciprocating magnet 101 and each of the two solenoid pairs 105-A, 104-A and 105-B, 104-B. The choice of this axial distance is an important consideration in the design of the transducer. Wherein the longer the shim, the greater the axial deflection available for acceleration of the reciprocating ring magnet 101 and thus the greater the force that can be generated.

The central axial stack of inner solenoids 104-a and 104-B, along with the central shim 110, form a structure having an outer surface adjacent to the inner boundary formed by the bore of the reciprocating ring magnet 101. The stack provides a guide member (center guide member) for the ring magnet 101. The central guide member passes through the aperture and the reciprocating magnet 101 is driven to reciprocate along its length. The central guide member also serves as a central linear bearing surface.

The outer axial laminations of the outer solenoids 105-a and 105-B, along with the outer shims 111, form a structure having an inner surface adjacent the outer boundary of the reciprocating ring magnet 101. The inner surface of the outer axial stack defines the outer boundary of the volume in which the reciprocating magnet is driven to reciprocate. The outer axial laminations form the outer guide member of the ring magnet 101 and also serve as the outer linear bearing surface.

In order for the linear bearing to remain free to move along the guide member, the coefficient of friction between the linear bearing and the guide member must be below a certain value (X) for a given ratio between the bearing length and the lever arm distance of the applied force (depending on the diameter or width of the reciprocating magnet). This avoids stick-slip effects during dynamic movement of the reciprocating magnet, which may temporarily bind with the surface of the guide member, resulting in non-linear movement.

The arrangement of the transducer 100 has the benefit of two guide members acting as linear bearing surfaces. This serves to reduce the occurrence of stick-slip effects. This is because this increases the critical value (X) below which free movement can be maintained, whereas stick-slip can occur. This provides the opportunity for a longer lever arm to be used for a given bearing length.

For the application of the transducer 100 described herein, the utilization of the inner and outer guide members allows the axial length (i.e., depth) of the reciprocating ring magnet 101 to be shorter, i.e., the bearing length of the reciprocating ring magnet 101 to be shorter, as compared to the use of only a single guide member with the apparatus, while avoiding stick-slip bonding of the reciprocating members to these guide members. This reduction in axial length causes a reduction in the overall profile of the transducer.

As described above, in order to avoid stick-slip, it is beneficial to reduce the coefficient of friction between the dynamic and static components. Thus, as shown in fig. 1A and 1B, transducer 100 may include elements 106 and 107, with elements 106 and 107 being static surfaces adjacent to and secured to the inner surfaces of the outer and outer axial stacks of the center axial stack. The static surfaces 106 and 107 may form part of the central guide member and the outer guide member, respectively. Specifically, the static surface 106 is adjacent to the inner boundary of the reciprocating magnet 101 and the static surface 107 is adjacent to the outer boundary of the reciprocating magnet 101.

The static surfaces 106 and 107 may be formed of, coated with, or laminated with a material that reduces friction between the reciprocating magnet 101 and the center and outer guide members. One material that has proven effective is to impregnate paperboard sleeves with epoxy with a graphite coating.

Additionally or alternatively, the reciprocating ring magnet 101 may also be coated or laminated with a low friction material. Further, the reciprocating ring magnet 101 may be assembled into or cast as a shoe (sabot), which may be formed of or coated with a low friction material. Although wear occurs due to the reciprocating motion of the magnet, the low friction layer or coating should have a sufficient thickness to maintain low friction for a long period of time.

Whether a guide member with a low friction surface layer and/or the reciprocating ring magnet 101, the gap between the magnetic surface of the reciprocating ring magnet and the magnetic surface of the solenoid should ideally be minimal in order to increase the electromechanical efficiency of the transducer.

In the case where such a transducer 100 is to be mass produced, the entire frame assembly including the solenoid but without the elements 108-a, 109-a may be formed in a single operation. Plastics that have inherent compliance to temperature changes while providing a long-term wear-resistant low friction surface may be used. Examples of good materials may be PEEK or PEEK and PTFE composites.

There are two reasons that the gap between the reciprocating ring magnet 101 and the low friction surface of the central guide member should be minimized. First, the minimum clearance reduces the amount of allowable axial deflection. This serves to improve the undesired mechanical resonance mode of the ring magnet 101 during dynamic movement (while, of course, allowing a sufficiently large gap to provide free movement of the ring magnet 101). A second aspect to be considered in relation to the gap relates to the working fluid surrounding the reciprocating ring magnet 101 and forming a volume 114 between the central guide member and the outer guide member, wherein the ring magnet 101 reciprocates in the volume. The gap should be selected such that the fluid surrounding the ring magnet 101 directly affects the movement of the ring magnet 101, but such that there is no significant fluid flow between the central guide member and the inner surface of the bore of the reciprocating ring magnet 101 and between the outer surface of the ring magnet 101 and the inner surface of the outer guide member. If a concentric tolerance of about 10 microns is obtained between the static and dynamic surfaces, and if the dynamic viscosity of the fluid is low, the gap may be selected such that the reciprocating ring magnet 101 slides smoothly over the guide member, wherein when the fluid is a gas, the fluid film around the reciprocating ring magnet 101 provides self-lubrication as an air bearing.

The central guide member and the outer guide member are maintained in a concentric configuration by connecting surfaces 108-a and 108-B, the connecting surfaces 108-a and 108-B spanning between the inner guide member and the outer guide member at either end of the guide member. These may be referred to as upper and lower (or first and second) connection surfaces 108-a and 108-B.

In addition to providing a connection surface between the inner and outer guide members, the connection surface may hermetically seal the volume 114 in which the reciprocating ring magnet 101 moves. The fluid within the volume 114 may be used to resist or inhibit the reciprocation of the magnet. This may have some benefits, such as suppressing external shock. Further, in some embodiments, a fluid (e.g., a gas component) may be selected (or omitted entirely, e.g., under vacuum) to create a particular level of damping (depending on compressibility) and/or to provide a particular frequency response of the transducer.

However, the primary application of transducers is to generate a reaction force by a moving mass. Thus, it is generally desirable to allow for maximum peak-to-peak amplitude displacement of the reciprocating magnet 101. Accordingly, it may be desirable to limit the motion of the reciprocating magnet as little as possible to improve the overall electromechanical efficiency of the transducer 100. Thus, the connection surfaces 108-A and 108-B may have an orifice or orifices 112-A and 112-B that allow fluid to flow into and out of the volume created between the central guide member and the outer guide member under the influence of the movement of the reciprocating ring magnet 101. However, such flow may be used in a more appropriate manner for haptic transducers that operate using the influence of reaction forces generated based on moving masses. In particular, the central guide member may include a bore 113, the bore 113 extending axially through the central guide member 104-B, 110, 104-a and being connected at either end to the volume 114 via one or more apertures 112-a, 112-B. For example, solenoids 104-A and 104-B may be wrapped or otherwise configured such that they have a central bore 113, and central bore 113 may be referred to as a central guide member fluid channel 113. The fluid channel 113 in the central guide member enables the fluid directly affected by the movement of the reciprocating ring magnet 101 to be redirected in a beneficial manner.

Specifically, as shown in fig. 2a and 2b, through an orifice (e.g., 112-a) in one of the connection surfaces (e.g., 108-a) that is part of the second fluid channel, fluid may be removed from the volume on the first side of the magnet 101 (i.e., the side toward which the magnet 101 moves) by the reciprocating magnet 101 and into the central guide member fluid channel 113. From the central guide member fluid channel 113, fluid flows through an orifice (e.g., 112-B) in a third fluid channel (of which the other one of the connection surfaces (e.g., 108-B) is a part) and into a portion of the volume 114 on the other side of the ring magnet 101. In this way, compression losses/damping can be avoided. The first and second fluid channels connecting the volume 114 to the central guide member fluid channel 113 may be accomplished with a simple disc having grooves sealed to the outer axial surfaces of the elements 108-a and 108-B, the disc being shown in the transducer 100 by the elements 109-a and 109-B.

Another benefit of this arrangement of fluid passages is that heat generated in the solenoids in the center guide members 104-a and 104-B can be effectively transferred to the fluid within the transducer 100 by the oscillating movement of the fluid due to the movement of the reciprocating ring magnet 101. The increased power delivered to the solenoid results in increased resistive heating, but is accompanied by a faster flow transfer rate of coolant through the center member bore 113. Such a method of heat dissipation may be preferable over other methods because the use of certain thermally conductive materials (e.g., aluminum or copper) within the transducer may cause eddy currents, which may cause problems for the performance of the transducer.

The fluid within the transducer may be a liquid or a gas. If a liquid is used, such a liquid with a magnetic particle composition may enable the frequency response of the transducer 100 to be changed by an external magnetic field. However, where minimal limitation of the reciprocation of the ring magnet 101 is required, gas may be preferred. The gas may be air or dry nitrogen, or may be a gas that is particularly effective for heat transfer, such as helium or hydrogen.

When heat from the inner solenoid is transferred to the fluid within the transducer 100, then heat is transferred to the reciprocating ring magnet 101 and the outer solenoids 105-a and 105-B, which results in more uniform heating of the transducer on the device. Heat may then be managed by extracting heat from the external member solenoids 105-a and 105-B using a thermal pathway, which may be a thermally conductive strip, which may be a metal such as copper or aluminum, or a heat pipe assembly, any of which may dissipate heat outside the transducer 100.

The violent movement of the reciprocating magnet 101 may cause the reciprocating magnet to collide with the repulsive fixed magnets 102-a and 102-B with sufficient force to damage the reciprocating magnet 101 or the fixed magnets 102-a and 102-B. Thus, the transducer may also comprise a material capable of absorbing vibrations and preventing direct impact between the reciprocating motion and the surface of the stationary magnet. Such material may be rubber. For example, sorbothane rubber exhibits useful properties such that damping the impact from an impact effectively reduces rebound, thereby reducing the audible sound produced by the impact.

Such vibration absorbing material, which is depicted in transducer 100 as elements 103-a and 103-B, may be located on dynamic reciprocating magnet 101 and may form part of its structure in a low friction shoe, or may be located on the surface of the stationary magnet facing reciprocating ring magnet 101.

Fig. 3 a-3 h illustrate exemplary variations in the configuration of fluid channels that may be incorporated into a transducer. Fig. 3a and 3b illustrate a "baseline" configuration of fluid channels, consistent with that shown and described with reference to fig. 1a, 1b, 2a and 2 b.

Fig. 3c shows the variation from the baseline depicted in fig. 3a and 3B by increasing the depth of the grooves formed in elements 109-a and 109-B. By increasing the depth, the resistance to fluid flow is reduced, thereby also reducing the resistance to movement of the reciprocating ring magnet 101 by extension.

Fig. 3d depicts a configuration in which the second fluid channel and the third fluid channel have more complex shapes. In particular, the first fluid channel and the second fluid channel may be configured without sharp edges, thereby facilitating equal flow resistance in whatever direction. This is desirable for efficient mechanical operation of the transducer 100 and to avoid turbulence that may lead to undesirable "fizzing" noise and loss of electromechanical efficiency.

Fig. 3e shows elements 109-a and 109-B having grooves deep enough compared to the thickness of disk 109 that the remaining material is flexible under pressure changes that occur during operation of transducer 100. Figure 3c shows the natural and deployed positions of the flexible region of the disc. This effect may supplement the tactile stimulus if the expanded areas of elements 109-a and 109-B are close to or in contact with the user's skin.

Fig. 3f, 3g and 3h illustrate various possible configurations of the orifices 112-a and 112-B forming part of the first and second fluid passages. More specifically, fig. 3f shows a larger diameter than the baseline, fig. 3g shows more orifices, and fig. 3h shows a modified shape than the baseline. This configuration may be used to reduce the resistance of the fluid path (fig. 3 f) to promote laminar flow out of the orifices 112-a and 112-B to reduce hissing noise (fig. 3 g) and redirect the flow effectively 180 degrees into the central member aperture 113 (fig. 3 h).

Fig. 4A and 4B show a simplified representation 300 of the magnetic field interaction in the transducer 100 between the solenoid 104A/105A or 104B/105B and the axially magnetized reciprocating magnet 101, as shown in fig. 4 c.

Fig. 4A shows the reciprocating magnet 101 in the form of a magnetic spring as described in the transducer apparatus 100 without an external repulsive force in the reciprocating magnet 101 in a natural magnetic equilibrium position within the energized solenoid pair (the inner solenoid 104-a/B is located within the bore of the reciprocating magnet 101 and the outer solenoid 105A/B is located around the outer boundary of the reciprocating magnet 101). The axial offset length of the reciprocating magnet 101 outside the axial extent of solenoids 104A/B and 105A/B is selected based in part on the natural magnetic equilibrium position of the reciprocating magnet 101 within the energized solenoid pair.

Fig. 4A also includes an enlarged view of half of the arrangement 300 depicting the reciprocating magnet 101 and the magnetic field lines of the central solenoid 104A/B and the outer solenoid 105A/B. These descriptions serve to illustrate how the center solenoid 104A/B affects the reciprocating magnet 101 more at the inner boundary/edge than at the outer boundary/edge of the reciprocating magnet 101. Also, it illustrates how the external solenoid 105A/B affects the reciprocating magnet more at the outer boundary/edge of the reciprocating magnet 101 than at the inner boundary/edge of the reciprocating magnet 101. By affecting the reciprocating magnet 101 at the inner and outer boundaries/edges, the magnetic influence of the static solenoids 104A/B and 105A/B on the reciprocating magnet 101 is increased compared to if only the inner or outer edges are affected by the magnetic influence of a similar solenoid. The effect is to increase the electromechanical efficiency of the transducer.

Fig. 4B shows an enlarged view similar to that provided in fig. 4a, except that in this case the reciprocating magnet is magnetically held in place (levitated) by stationary magnets 102-a and 102-B (not shown). The reciprocating magnet 101 maintains a position that is a distance that exceeds the axial surface range of solenoids 104A/B and 105A/B. The distance beyond the extent of the solenoid axial surface is determined by the length of the center axial shim 110 and the outer shim 111. The magnetic flux lines depicted in fig. 4B are helpful in understanding the magnetic interactions that occur between the reciprocating magnet 101 and solenoids 104A/B and 105A/B during the transient time that the solenoids are energized. The extent to which the force on the reciprocating ring magnet 101 is affected by solenoids 104A/B and 105A/B depends on the number of distorted flux lines between the static solenoid and the reciprocating magnet. If the central axial shim 110 and the outer shim 111 are selected to be of increased length (i.e., the spacing between the upper and lower pairs of solenoids is increased), the reciprocating ring magnet 101 will have a further free axial offset distance, providing a greater distance to allow for higher accelerations and forces to be generated. However, as a result, the reciprocating magnet is held farther by the fixed magnets 102-A, 102-B than by the solenoids 104A/B and 105A/B, and therefore has a lower electromechanical efficiency. Thus, it is beneficial to choose the axial distance that has been optimized to maximize the magnetic influence of solenoids A/B and 105A/B on the reciprocating ring magnet 101 as well as the axial displacement, while keeping in mind the entire depth of the transducer device 100 in the application of wearable technology.

Fig. 5 a-5 f are different views of various configurations that may be employed for the fixed magnets 102a and 102-B of the repulsive magnetic spring assembly that levitate the reciprocating magnet 101. Fig. 5a and 5b depict one exemplary configuration of a fixed magnet. As shown, in fig. 5b (and fig. 5 d), the fixed magnet may be a ring magnet.

As shown in fig. 5 c-5 f, the configuration of the fixed magnet may be modified/selected based on the desired magnetic spring rate while maintaining a uniform force across the axial surface extent of the reciprocating magnet (i.e., the major surface of the reciprocating magnet connecting the outer boundary to the inner boundary). Unequal forces from the repelling magnets 102-a and 102-B across the axial surface extent of the reciprocating magnet 101 may cause uneven wear of the inner and outer guide members or undesirable mode vibration of the reciprocating magnet 101.

Thus, the repelling fixed magnets 102-A and 102-B should be selected such that their shapes provide equal forces on the reciprocating ring magnet 101. Thus, it may be desirable for the fixed magnets 102-A and 102-B to have a shape similar to that of a reciprocating magnet. Thus, where the reciprocating magnet is a ring magnet, the stationary magnet may also be a ring magnet having an axial surface area and shape similar to that of reciprocating ring magnet 101.

When compared to the configuration of fig. 5a and 5B, fig. 5c depicts an increase in the axial depth of the fixed magnets 102-a and 102-B, while the ring magnet of fig. 5e has a reduced axial depth. Since the axial depth of the permanent magnet is related to the surface magnetic field flux for a given material, increasing the axial depth of any magnet within the magnetic spring will result in a higher spring rate and vice versa for decreasing the thickness of the magnet. The magnetic spring rate and mass of the magnet should be selected so that it has a natural resonance at the desired operating frequency of the transducer 100.

As shown in fig. 5d, the fixed magnets 102-a and 102-B may only partially cover the area of the reciprocating ring magnet 101 to reduce the magnetic spring rate while maintaining equal force over the axial surface of the ring magnet 101.

As shown in fig. 5f, each of the fixed magnets 102-a and 102-B may be formed of a plurality of magnets. They are equally spaced from each other and are provided in an arrangement depending on the shape of the main surface of the reciprocating magnet (so they are arranged in a ring shape in this example). The use of multiple small magnets (e.g., small disc magnets) rather than a single magnet may allow a wider range of magnetic stiffnesses to be obtained, as a greater number may be arranged. This arrangement of the small magnets may be such that there is a radial force gradient across the span of the axis between the central guide member and the outer guide member. This arrangement can be used to reduce the possibility of stick-slip effects by having a higher spring force in the center of the reciprocating ring magnet 101 than the outer span.

Fig. 6 a-6 c illustrate various examples of the spacing between solenoid pairs 104-a/105-a and 104-B/105-B and the offset length beyond their outer axial surfaces. The center-to-center spacing between solenoids depends on the length of the center spacer 110 and the outer spacer 111. As previously mentioned, the length selection is a compromise between the potential magnetic coupling and the available offset distance of the reciprocating magnet 101. This is because if the length of the shim is equal to the axial length (also referred to as depth) of the reciprocating magnet 101 such that the two outer axial surface extents of the reciprocating magnet 101 are aligned with the inner axial surface extents of the solenoid pairs 104-a/105-a and 104-B/105-B, the solenoid's available force against the reciprocating magnet reaches its maximum. However, the usable offset distance of the ring magnet 101 before the preferred equilibrium as shown in fig. 4a is reached is short, and thus the maximum usable acceleration is limited. For a given distance, the solenoid's impact on the magnet decreases in an inverted cube (inverted cube). Thus, as shown in fig. 6c, shims 110, 111 that are longer than the axial length of the ring magnet 101 may result in less force being generated on the reciprocating magnet 101 under the electromagnetic influence of the solenoid, resulting in lower transducer efficiency.

The arrangement of fig. 6a has shims 110, 111, the shims 110, 111 being about 20% longer than the axial length of the reciprocating ring magnet 101 and has been found to be an effective compromise between the usable offset length of the ring magnet 101 and the electromagnetic coupling between the solenoid pairs 104-a/105-a and 104-B/105-B and the magnet 101. As will be appreciated, other shim lengths may alternatively be used. For example, the spacing between the upper and lower solenoids may be 10% to 30% longer than the depth of the reciprocating magnet, or 15% to 25% longer than the depth of the reciprocating magnet, or 17.5% to 22.5% longer than the depth of the reciprocating magnet.

Fig. 6B shows that the external offset distance (i.e., the length of the volume over which the magnet can reciprocate above and below the solenoid) within elements 108-a and 108-B is increased compared to the configuration shown in fig. 6 a. With this configuration, there is a trade-off between the total transducer axial length (i.e., how thick/deep it is) and the available offset of the ring magnet 101. The increase in offset length beyond the outer axial length of the solenoid pairs 104-A/105-A and 104-B/105-B allows for deeper shock mitigation strategies, such as foam, between the reciprocating magnet 101 and the stationary magnets 102-A and 102-B. In addition, deeper spring magnets 102-A and 102-B may be used.

Fig. 7 shows that a transducer 100 consisting of a high strength permanent magnet and solenoid, which may not have an internal magnetic return path, may have a high stray magnetic field. Thus, the transducer may include magnetic shielding to manage such stray magnetic fields.

The external magnetic shielding of the transducer device 100 may be provided by using an external yoke. The yoke may be composed of low carbon steel or single grain high silicon steel laminations oriented in such a way as to form a complete magnetic circuit for stray fields. Another possible material is Mu metal, which is a nickel-iron alloy exhibiting high magnetic permeability.

In order to minimize eddy current losses in the magnetic shield, it is preferable to use several layers of Mu metal foil, with each inner layer being electrically isolated from the next outer layer, rather than a single layer of sufficient thickness to shield the transducer device 100 from stray magnetic fields. This is illustrated by the element 501 surrounding the transducer.

Additionally or alternatively, the transducer may include elements 502 and 503, the elements 502 and 503 being rings of non-ferromagnetic but electrically conductive material (e.g., aluminum or copper) embedded within the inner and outer pads 110 and 111. These elements may be used to actively generate eddy currents under the inductive influence of the reciprocating motion of the ring magnet 101, thereby changing the overall frequency response of the transducer apparatus 100. Such frequency changes have the passive effect of a low pass filter, and such a configuration may also inhibit damage to the transducer from external shock by limiting the amount of possible acceleration of the reciprocating ring magnet 101.

Fig. 8a and 8b show two views of an exemplary transducer 700, the transducer 700 being a modified version of the transducer 100 shown in the previous figures comprising a single reciprocating magnet 101.

In the example of fig. 8a and 8b, the transducer includes a plurality of reciprocating (e.g., annular) magnet elements 702, 704, and 706, which are concentrically positioned with respect to one another. In this configuration, magnets having a larger diameter have increased mass compared to magnets having a smaller diameter. An advantage of using a plurality of reciprocating ring magnets of different masses is that each reciprocating ring magnet suspended within its own magnetic spring will have its own resonant frequency and bandwidth. Thus, the operating bandwidth of the overall transducer 700 may be widened.

As with the transducer 100 of the previous figures, the reciprocating magnet 101 reciprocates on inner and outer guide members, each reciprocating magnet in the apparatus 700 also having guide members at the inner and outer boundaries of the reciprocating magnet. For the inner reciprocating magnet 702, the inner boundary slides on the low friction surface 708 around the inner first guide member and the outer boundary of 702 slides on the surface 709 around the second guide member. The magnetic springs are formed by placing fixed repulsive magnets above and below the axial extent of the inner reciprocating magnet 702, shown as elements 714-a and 714-B.

This arrangement is similar for the intermediate reciprocating magnet 704, with the intermediate reciprocating magnet 704 having an inner boundary guided by a surface 710 on the third guide member and an outer boundary of 704 guided by a 711 on the fourth guide member. 704 are formed of fixed magnets 715-a and 715-B.

The outer reciprocating magnet 706 has an inner boundary that slides on a low friction surface 712 surrounding the fifth guide member, and the outer boundary of 706 slides on a surface 713 on the inner surface of the sixth guide member. The magnetic springs are formed by placing fixed magnets above and below the axial extent of the outer reciprocating ring magnet 706, shown as elements 716-a and 716-B.

For each reciprocating magnet in transducer 700, as with transducer 100, each reciprocating magnet may be moved by the influence of the magnetic field of the solenoid, which influences the axial extent of the inner edge of the center bore of the reciprocating magnet, above and below, and the axial extent of the outer edge of the reciprocating magnet. For the inner reciprocating magnet 702, the inner edge is affected by the axial stack of elements 701-a and 701-B held between shims and forming the first guiding member. The outer edge of magnet 702 is affected by the axial stack of elements 703-a and 703-B which are held between the shims and form the second guiding member.

For intermediate reciprocating magnet 704, the inner edge is affected by the axial stack of elements 703-a and 703-B that are held between the shims and form the third guide member. The outer edge of the ring magnet 704 is affected by the axial stack of elements 705-a and 705-B which are held between shims and form the fourth guiding member.

For the outer reciprocating magnet 706, the inner edge is affected by the axial stack of elements 705-a and 705-B that are held between the shims and form the fifth guiding member. The outer edge of the reciprocating magnet 706 is affected by the axial stack of elements 707-a and 707-B held between the shims and forming a sixth guiding member.

Fig. 9 illustrates a typical application of the transducer device 100 embedded in an article of footwear 900-X in this case. The illustrated article of footwear may be one half of a pair (900-X, 900-Y) of similarly configured articles of footwear, each of which includes a respective transducer and is generally configured as described below.

The article of footwear 900-X includes an upper element 901 and a sole (sole), wherein the transducer element 100 (or 700) may be embedded in a heel portion of the sole. The heel and sole are the highest pressure points of the human foot and therefore most in contact with the sole of the shoe. Thus, placing the transducer in the heel portion of the sole may maximize the feel experienced by the wearer. Furthermore, the heel is directly aligned with the leg, so that vibrations of the user's heel will be transferred up to the body as occurs naturally when low frequency ground vibrations interact with a standing person. To maintain a relatively thin sole, the article of footwear includes a single transducer, with the transducer 100 being located in the center of the heel region of the footwear.

The transducer 100 generates heat primarily through resistive losses in the solenoid. The heat generated is managed by transferring the heat via a thermally conductive path to a heat sink 904 placed outside the sole. Such a heat sink 904 may be shaped or characterized by the ornamental design of the shoe. The power amplifier (not visible) of the transducer 100 may be close to the transducer and heat sink to minimize transmission distance loss and reduce the total number of heat sink areas required by using a single heat sink for both the transducer and the amplifier.

Sole 902 also includes a recess in which wireless communication signal processing, power amplification, and batteries may be located. These may be provided in a single module 903, and the module 903 may be removed from the sole 902 for maintenance and/or to recharge the battery. Wireless communication signal processing, power amplification, and battery 903 may be located in the arch region between the toe and heel portions of the sole.

Fig. 10 illustrates a tactile stimulation system that includes a first vibratory device 900-X (e.g., the first article of footwear illustrated in fig. 9) and a second vibratory device 900-Y (e.g., similar to the second article of footwear illustrated in fig. 9). For brevity, the vibratory apparatuses 900-X and 900-Y will be referred to as first shoes and second shoes. However, it will be appreciated that this is not limited thereto.

The first shoe 900-X of the pair of shoes includes a first transducer 100-X (or 700), the first transducer 100-X (or 700) being configured to convert a first electrical signal into a vibratory motion. The first shoe 900-X further includes a first wireless receiver 1103-X, the first wireless receiver 1103-X being configured to wirelessly receive a first data signal transmitted via a first communication protocol. The first wireless receiver 1103-X may be a bluetooth (e.g., bluetooth 4.2) audio (e.g., stereo audio) receiver element 1103-X.

The first shoe may further include a first wireless transmitter configured to wirelessly transmit the second audio signal via a second, different communication protocol. For example, the second communication protocol may be an RF UHF protocol. The use of such a different protocol (a protocol other than bluetooth) may help minimize any delay between the frequency response of the first transducer 100-Y at the second shoe 900-Y and the transducer 100-X at the first shoe 900-X.

The first shoe 900-X may also include a processing device 1109-X, the processing device 1109-X being configured to generate and provide a first electrical signal to the first transducer 100-X (for inducing vibrations in the transducer) based on the wirelessly received first audio signal. Further, the processing device 1109-X is configured to provide a second audio signal derived from the wirelessly received first audio signal for transmission by the first wireless transmitter 1108. The first wireless transmitter 1108 may transmit the second audio signal via a communication protocol that is different from the communication protocol that received the first audio signal.

More specifically, the (first) audio signal received by the receiver 1103-X is passed to a first filter 1106-X. In some examples, the audio signal may be passed to filter 1106-X via a mixer. In examples where the signal is a stereo audio signal, the stereo signal of only one of the two channels may be passed to the first filter 1106-X.

The first filter may be a controllable band pass filter 1106-X in which one or more bandwidths may be modified along with an upper cut-off and a lower cut-off. The signal from the first filter 1106-X may then be passed to and on to the power amplifier 904-X to cause vibration to occur.

The received stereo audio signal of the other channel may be passed to a second filter 1107-X. The second filter 1107-X may be a controllable band pass filter in which one or more bandwidths and upper and lower cutoffs may be modified.

The signal output by the second filter 1107-X may then be passed to the first wireless transmitter 1108 and transmitted by the first wireless transmitter 1108. As described above, the first wireless transmitter 1108 may transmit signals using a different protocol than the protocol that receives the first audio signal.

In examples where the received signal is not stereo, the output of the first filter 1106-X may also be passed to the transmitter.

In some examples, the first shoe may include a digital audio player 1105. In such an example, the signal output by the first receiver 1103-X may be passed to the audio mixer 1104-X, which audio mixer 1104-X also receives audio from the on-board digital audio player element 1105 in another channel. The audio mixer is capable of selectively providing the first transducer 100-X (and the second shoe) with audio signals received by the receiver or audio signals output by the on-board digital audio player. In some examples, an on-board digital audio player may play audio when the device 900-X/Y is powered on, or may be used to play calibration tracks for performance feedback measurements.

The signal from audio mixer 1104-X may be passed to the first filter similar to that described above.

Power for shoe 900-X may be delivered from on-board battery 1113-X. System power may be managed by module 1112-X and system power may be managed by element 1110-X.

The on-board battery 1113-X may also include inductive wireless charging whereby an external oscillating electromagnetic field from a charging pad (not shown) excites the inductive coil 1115-X so that power may be transferred wirelessly between the charging pad and the inductive coil 1115-X. The power from the inductive coil 1115-X passes through the charge management device 1115-X.

The various functions of the first shoe 900-X may be controlled or monitored by the processing device 1109-X, which processing device 1109-X may be a microprocessor. Further, the first shoe may include user input devices 1111-X (e.g., buttons) to enable a user to provide commands directly to the shoe.

The second shoe 900-Y includes a second transducer 900-Y (e.g., any of the transducers described above) configured to convert a second electrical signal into vibratory motion.

The second shoe also includes a second wireless receiver 1116, the second wireless receiver 1116 being configured to wirelessly receive audio signals transmitted by the first wireless transmitter 1108 of the first shoe via a second communication protocol (e.g., RF UHF).

The second shoe may also include a second processing device 1109-Y, the second processing device 1109-Y being configured to cause generation of a second electrical signal based on an audio signal received by the wirelessly received second wireless receiver 1116 and provide it to the second transducer.

The operation of the audio processing functions of second shoe 900-Y may be similar to the operation described with reference to first shoe 900-X. Specifically, the signal output by the second wireless receiver 1116 may be provided to a third filter 1106-Y, which may be a controllable band-pass filter such as that described with reference to the first shoe 900-X. The output of the third filter 1106-Y may be provided to a second power amplifier 904-Y. The output of the second power amplifier is then provided to the second transducer 100-Y.

The second shoe may also have the on-board battery and battery-related functions described with reference to the first shoe 900-X.

Like the first shoe, all functions of the second shoe 900-Y may be controlled or monitored by the processing device 1109-Y, which may be a microprocessor. Further, second shoe 900-Y may include user input devices 1111-X (e.g., buttons) to enable a user to provide commands directly to the shoe.

Before bluetooth 5.0, which would have two devices (i.e., the shoe and the user's headset 1102) connected to the user's mobile device 1000, are co-distributed, the system may require a dual bluetooth transmitter as described in element 1101 to have audio transmitted to the user's headset 1102 and the first shoe 900-X. The use of such dual transmitters ensures that the signal delay between the user's audio device 1100 and the bluetooth headset and shoe is similar.

An alternative solution is to include another bluetooth transmitter in one of the shoes, which transmits to the headset. However, the signal from the bluetooth receiver on the shoe to be transmitted to the processor and subsequent transducer requires an artificial delay to be added to the signal to match the shoe's delay through bluetooth to the user's headset. For practicality, a dual bluetooth transmitter is provided outside the footwear to allow for more audio device options to be provided that can be connected to both the user's headset and the shoe at the same time.

The processing devices 1109X, 1109-Y may include at least one processor (also referred to as a processing device) communicatively coupled to a memory (not shown). The memory may have computer-readable instructions stored thereon that, when executed by the processor, cause the various operations described with reference to the above figures to be performed.

The at least one processor may have any suitable composition and may include one or more processors of any suitable type or combination of suitable types. For example, at least one processor may be a programmable processor that interprets computer program instructions and processes data. The at least one processor may comprise a plurality of programmable processors. Alternatively, the at least one processor may be programmable hardware, for example with embedded firmware. The at least one processor, which may be referred to as a "processing device," may alternatively or additionally include one or more Application Specific Integrated Circuits (ASICs). In some cases, the processing device may be referred to as a computing device.

The at least one processor is coupled to a memory (which may be referred to as one or more storage devices) and is operable to write data to the memory 503-2 or read data from the memory 503-2. The memory may include a single memory unit or multiple memory units, with computer-readable instructions (or code) stored on the memory units. For example, the memory may include both volatile memory and nonvolatile memory. For example, computer readable instructions/program code may be stored in a non-volatile memory and executed by at least one processor using the volatile memory to temporarily store data or data and instructions. Examples of volatile memory include RAM, DRAM, SDRAM, and the like. Examples of non-volatile memory include ROM, PROM, EEPROM, flash memory, optical storage, magnetic storage, and the like. These memories may be generally referred to as non-transitory computer-readable storage media.

The term "memory" encompasses, in addition to memory including both non-volatile memory and volatile memory, only one or more non-volatile memory, or both one or more volatile memory and one or more non-volatile memory.

Embodiments of the invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic, and/or hardware may reside on the memory or any computer medium. In an exemplary embodiment, the application logic, software, or instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a "memory" or "computer-readable medium" can be any medium or means that can contain, store, communicate, propagate, or transport the instructions for use by or in connection with the instruction execution system, apparatus, device, or use by a computer.

In related cases, references to "computer-readable storage medium", "computer program product", "tangibly embodied computer program", etc., or "processor" or "processing apparatus", etc., are to be understood to include not only computers having different architectures such as single/multiprocessor architectures and sequencer/parallel architectures, but also special-purpose circuits such as Field Programmable Gate Arrays (FPGA), application specific circuits (ASIC), signal processing devices, and other devices. References to computer programs, instructions, code etc. are to be understood as representing software of a programmable processor firmware, such as the programmable content of a hardware device or a configuration setting of a fixed function device, gate array, programmable logic device etc. as instructions of a processor.

The different functions discussed herein may be performed in a different order and/or concurrently with each other, if desired. Furthermore, one or more of the above-described functions may be optional or may be combined, if desired. Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

It should also be noted herein that while various examples are described above, such descriptions should not be considered limiting. Rather, several changes and modifications may be made without departing from the scope of the present invention as defined in the appended claims.

Claims

1. A transducer configured to convert an electrical signal into vibratory motion, the transducer comprising:

an axially magnetized reciprocating magnet magnetically levitated between a first axially magnetized fixed magnet and a second axially magnetized fixed magnet on opposite sides of the axially magnetized reciprocating magnet, wherein the axially magnetized reciprocating magnet includes a bore such that the reciprocating magnet has an inner boundary and an outer boundary; and

At least two concentrically positioned pairs of electromagnetic solenoids configured to drive the reciprocating magnet to reciprocate in a volume between the first axially magnetized fixed magnet and the second axially magnetized fixed magnet,

wherein a first solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is positioned to affect the reciprocating magnet more at the inner boundary than at the outer boundary and a second solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is positioned to affect the reciprocating magnet more at the outer boundary than at the inner boundary.

2. The transducer of claim 1, wherein the first solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is located within the bore of the reciprocating magnet and the second solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is located outside the outer boundary of the reciprocating magnet when viewed along the axis of reciprocation of the axially magnetized reciprocating magnet.

3. The transducer of any of claims 1 and 2, comprising a central guide member, wherein the volume in which the reciprocating magnet is driven to reciprocate surrounds the central guide member and the central guide member extends through the aperture of the reciprocating magnet, the at least two concentrically positioned pairs of electromagnetic solenoids configured to drive the reciprocating magnet to reciprocate along a length of the central guide member.

4. A transducer according to claim 3, comprising an outer guide member surrounding and defining an outer boundary of the volume in which the reciprocating magnet is driven for reciprocating motion.

5. The transducer of claim 4, wherein an outer surface of the center guide member adjacent the inner boundary of the reciprocating magnet and an inner surface of the outer guide member adjacent the outer boundary of the reciprocating magnet are formed of a material that reduces friction between the reciprocating magnet and the center guide member and the outer guide member.

6. The transducer of any of claims 4 or 5, wherein the second solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is located within or forms part of the outer guide member.

7. A transducer according to claim 3, wherein the first solenoid of each of the concentrically positioned pairs of electromagnetic solenoids is located within or forms part of the central guide member.

8. A transducer according to claim 3, wherein:

The central guide member includes a central guide member fluid passage extending through a central region of the central guide member to allow fluid to flow through the central region of the central guide member, the central region being between a first end of the central guide member and a second end of the central guide member;

the transducer includes at least one second fluid channel configured to allow fluid to pass between the volume of the axially magnetized reciprocating magnet driven for reciprocation and the first end of the central guide member fluid channel; and is also provided with

The transducer includes at least one third fluid channel configured to allow fluid to flow between the volume of the axially magnetized reciprocating magnet driven for reciprocation and the second end of the central guide member fluid channel.

9. The transducer of claim 8, wherein the transducer is sealed.

10. A transducer according to claim 1 or 2, comprising a vibration absorbing material disposed between the axially magnetized fixed magnet and the reciprocating magnet.

11. The transducer of claim 10, wherein the vibration absorbing material is disposed on a surface of the axially magnetized fixed magnet facing the reciprocating magnet.

12. The transducer of claim 10, wherein the vibration absorbing material is disposed on a surface of the reciprocating magnet facing the axially magnetized fixed magnet.

13. A transducer according to claim 1 or 2, comprising a magnetic shield to magnetically shield the environment surrounding the transducer from the magnets of the transducer.

14. The transducer according to claim 1 or 2, wherein the reciprocating magnet comprises:

a first main surface facing the first axially magnetized fixed magnet;

a second main surface facing the second axially magnetized fixed magnet;

an inner surface extending between the first and second major surfaces at the inner boundary of the reciprocating magnet; and

an outer surface extending between the first and second major surfaces at the outer boundary of the reciprocating magnet,

and wherein:

an edge of the first solenoid in a first one of the concentrically positioned pairs of electromagnetic solenoids is positioned adjacent to an edge of the reciprocating magnet connecting the first major surface and the inner surface;

An edge of the first solenoid in a second of the concentrically positioned pairs of electromagnetic solenoids is positioned adjacent to an edge of the reciprocating magnet connecting the second major surface and the inner surface;

an edge of the second solenoid in the first of the concentrically positioned pairs of electromagnetic solenoids is positioned adjacent an edge of the reciprocating magnet connecting the first major surface and the outer surface; and is also provided with

An edge of the second solenoid in the second pair of the concentrically positioned pairs of electromagnetic solenoids is positioned adjacent to an edge of the reciprocating magnet connecting the second major surface and the outer surface.

15. An article of footwear comprising the transducer of any of the preceding claims.

16. The article of footwear of claim 15, comprising an amplifier positioned adjacent to the transducer and configured to provide an electrical signal to the transducer.

17. The article of footwear of claim 15 or 16, comprising a removable module including a battery and a transceiver for receiving wireless signals, the electrical signals provided to the transducer being generated based on the wireless signals.

18. A tactile stimulation system, the tactile stimulation system comprising:

a first vibration device and a second vibration device,

wherein the first vibration device includes:

a first transducer configured to convert a first electrical signal into a vibratory motion, the first transducer being a transducer according to any one of claims 1 to 14;

a first wireless receiver configured to wirelessly receive a first data signal transmitted via a first communication protocol;

a first wireless transmitter configured to wirelessly transmit second data signals via a different second communication protocol; and

a first processing device configured to:

generating the first electrical signal based on the first data signal received wirelessly and providing the first electrical signal to the first transducer, and

generating the second data signal based on the first data signal received wirelessly and providing the second data signal to the first wireless transmitter for transmission by the first wireless transmitter; and is also provided with

Wherein the second vibration device includes:

a second transducer configured to convert a second electrical signal into a vibratory motion, the second transducer being a transducer according to any one of claims 1 to 14;

A second wireless receiver configured to wirelessly receive the second data signal transmitted by the first wireless transmitter of the first vibratory device via the second communication protocol; and

a second processing device configured to:

generating the second electrical signal based on the wirelessly received second data signal and providing the second electrical signal to the second transducer,

wherein the first electrical signal and the second electrical signal cause the first transducer and the second transducer to vibrate at substantially the same frequency response.

19. The tactile stimulation system of claim 18, comprising an audio player or an accessory of an audio player, wherein the audio player or accessory of an audio player comprises:

a second wireless transmitter configured to wirelessly transmit the first data signal to the first wireless receiver at the first vibration device via the first communication protocol, the first data signal generated based on an audio data signal output by the audio player; and

a third wireless transmitter configured to wirelessly transmit the second data signal to an audio speaker.

20. The tactile stimulation system of claim 19, wherein the third wireless transmitter is configured to wirelessly transmit the first data signal to the audio speaker via the first communication protocol.

21. The tactile stimulation system of any one of claims 18 to 20, wherein the first communication protocol is a bluetooth protocol and/or the second communication protocol is an RF UHF communication protocol.

22. The tactile stimulation system of any one of claims 18 to 20, wherein the first vibration device is disposed in a first article of footwear of a pair of articles of footwear and the second vibration device is disposed in a second article of footwear of the pair of articles of footwear.